A laminated glass is widely used as window glasses for automobiles, for railroad car, for aircrafts, for ships, for buildings and for many others, because the laminated glass can contribute to safety. There is little scattering of glass fragments when an impact out of the outside is applied to the laminated glass.
The laminated glass is made of at least a pair of sheet glasses, and an interlayer which is interposed between the pair of sheet glasses. For example, a plasticized polyvinyl acetal resin film, an ethylene-vinyl acetate copolymer resin film, an ethylene-acrylic copolymer resin film, a polyurethane resin film, a polyurethane resin film containing sulfur, and a polyvinyl alcohol resin film are generally used as the interlayer for the laminated glass.
The Patent Document 1 discloses a film formed of a plasticized polyvinyl butyral which is plasticized by a multiester of an alcohol having 2-4 hydroxyl groups and C16-C20 unsaturated fatty acid having a hydroxyl group bonded to an oxygen molecule. In the Patent Document 1, the interlayer for a laminated glass includes, a monoester component of a glycol and a C16-C20 unsaturated fatty acid having a hydroxyl group bonded to an oxygen molecule in addition to the above multiester component. The Patent Document 1 describes that the total amount of a mixed plasticizer in the interlayer should be 10-55 phr on a weight basis to 100 phr of PVB resin.
The Patent Document 1 describes that, when a laminated glass is prepared by using the said plasticized polyvinyl butyral film, an adhesive strength in a peeling test is proper, and penetration resistance of the laminated glass is excellent over a wide range of temperature.
The Patent Document 2 discloses an interlayer containing 50-80 weight % of PVB (acetalized polyvinyl alcohol) resin and 20-50 weight % of a softener. In the interlayer described in the Patent Document 2, 30-70 weight % of the softener is composed of polyalkylene glycols represented by the following formula (A1) to (A6) or the derivatives thereof.HO—(R—O)n—H  (A1)In the formula (A1), R is an alkylene group and n>5HO—(CH2—CH2—O)n—(CH2—CH(CH3)—O)m—H  (A2)In the formula (A2), n>2, m>3 and (n+m)<25R1O—(CH2—CH2—O)n—(CH2—CH(CH3)—O)m—H  (A3)HO—(CH2—CH2—O)n—(CH2—CH(CH3)O)m—R1  (A4)In the formula (A3) or (A4), n>2, m>3, (n+m)<25 and R1 is an organic groupR1—O—(R2—O)n—H  (A5)In the formula (A5), R2 is an alkylene group, n≧2 and R1 is an organic groupR1—O—(R2—O)n—R3  (A6)In the formula (A6), R2 is an alkylene group, n>5, and R1 and R3 are organic groups
Since the interlayer described in the Patent Document 2 contains the specific compound as the softener in the specific ratio, sound insulating property can be obtained for the laminated glass obtained by using the interlayer.
Patent Document 1: JP 60-60149 A
Patent Document 2: WO 01/19747 A1